The present invention relates to an interluminal prosthesis for intraluminal repair of body conduits. More specifically, the present invention relates to intraluminal repair of aneurysms using an arterial interluminal prothesis. Furthermore, the present invention relates to a method of implanting the interluminal prosthesis in an artery. The invention especially relates to an arterial interluminal prosthesis having a tubular form where one end of the tube is connected to the thoracic aorta and the other end is bifurcated to form two tubular passageways and each passageway is connectable to each of the iliac arteries.
Interluminal devices for repairing body conduits are well known to the art. Such devices include tubular flexible grafts that are implanted by the use of stents. Stents are a means of attachment of intravascular prostheses.
With special reference to abdominal aortic aneurysms, such aneurysms occur because of an abnormal dilation of the wall of the aorta within the abdomen. Surgical procedures involving the abdominal wall are major undertakings with high associated risk together with considerable mortality. The replacement of the aorta with surgical procedures involves replacing the diseased portion of the vessel with a prosthetic device which is typically formed of a synthetic tube or graft, usually fabricated of Dacron(copyright), Teflon(copyright), or other suitable material. In the surgical procedure, the aorta is exposed through an abdominal incision. The aorta is closed both above and below the aneurysm so that the aneurysm can be opened and any thrombus and arteriosclerotic debris can be removed. A graft of approximately the size of a normal aorta and is sutured in place to replace the aneurysm. Blood flow is then reestablished through the graft. Surgery according to the prior art required an extended recovery period together with difficulties in suturing the graft to the aorta.
In the European patent application to Barone et al., number 0,461,791 A1, a method is disclosed for repairing an abdominal aortic aneurysm which includes a tubular graft that is intraluminally delivered through the iliac artery and secured to the aorta by the expansion and deformation of a stent. In the application, a tube is disclosed which has a single end that is bifurcated to two other ends each of which is attached to one of the iliac arteries. Such disposition of the graft can provide a reduction in the trauma of the surgery because the graft is delivered to the site intraluminally. While one connection to an iliac artery is reasonably easy to accomplish, rather complicated techniques are required to move the other leg of the graft to the other iliac artery and connect it thereto.
A patent to Parodi et al., U.S. Pat. No. 5,219,355, discloses a balloon device for implanting an aortic interluminal prosthesis to repair aneurysms. In the patent, a graft prothesis is disposed upon a catheter having two balloons mounted thereon. The prosthesis is mounted on the catheter and stents are mounted upon the balloons. The assembly of the graft, the two balloons and the stents are introduced into the aneurysm by catheterization. The balloons are inflated to implant the prosthesis within the aneurysm and affix the stents against the artery walls, thereby to repair the aneurysm. The balloons are deflated and the catheter is withdrawn.
According to the present invention I have discovered an interluminal prothesis especially useful for intraluminal repair of aneurysms. The prothesis includes a generally tubular flexible graft of conventional prosthetic graft material having a proximal open end and at least one leg with a distal open end and preferably two legs with two distal open ends. Preferably, a first stent is disposed within and attached to the proximal open end. The first stent emerges from the proximal open end and is adapted to be attached to the aorta intraluminally. A hem terminating in the distal open end of the graft is inverted within the leg. The hem is arranged as a cuff within the leg. A second stent having a proximal and a distal end can be attached to the interior of the distal end of the cuff so upon withdrawing the second stent from the cuff, the cuff will unfold and follow the stent for implantation of the graft. In a preferred embodiment the graft is bifurcated at one end to form two legs, each terminating in distal open ends. Each leg is attached to one of the iliac arteries. In the preferred embodiment also, the hem is inverted a second time to form a second cuff within the first cuff. The stent extends outwardly from the distal open end of the second cuff. Many of the stents are devices which are deformed by increasing the diameter until they engage a wall of a body conduit and are anchored thereto. Alternatively they may be integrally knitted into the graft or they may be polymeric impregnations of the graft which harden upon heating to enable the hardened impregnation to engage the body conduit.
To dispose the graft within the aorta a conventional guidewire is threaded through the iliac artery into the aorta using conventional techniques. A delivery catheter is then threaded over the guidewire until it reaches the desired location within the aorta. A graft having at least two open ends is disposed on the delivery catheter. Each open end of the graft can have a stent disposed therein. The portion of the graft that is adapted to be attached to the aorta has the stent extending outwardly from its open end so that the graft may be attached to the aorta. In the case of a bifurcated graft in which two legs of the graft are to be attached to the two iliac arteries branching from the aorta, one of the legs can have a stent extending outwardly from its open end. The other leg of the graft is disposed inside the graft leg in the form of a cuff which is inverted into itself at the open end. A stent can be attached to the cuff. A balloon catheter is disposed near the end of the inverted leg. The inside of the inverted leg is engaged by the balloon and is withdrawn through the other iliac artery. When appropriately positioned within the iliac artery, the stent is expanded to engage the artery and set it. The balloon and then the guidewire is then withdrawn from the artery and the procedure is completed.